Question

Statement I: Though the same current flows through the line wires and the filament of the bulb but heat produced in the filament is much higher than that in line wires.
Statement II: The filament of bulbs is made of a material of high resistance and high melting point.

• A. If both statements are true and statement II is the correct explanation of statement I.
• B. If both statements are true but statement II is not the correct explanation of statement I.
• C. If statement $I$ is true but statement II is false.
• D. If both statements are false.

Answer 1

Answer: (A)

As filament of bulb and line wire are in series, hence current through both is same. Now, because $H=\frac{i^{2}Rt}{4.2}$ and resistance of the filament of the bulb is much higher than that of line wires, hence heat produced in the filament is much higher than that in line wires.